Beneath WWI trenches in France, carvings in the stone of underground bunkers where men lived for long periods of time during World War I became a poignant expression of the horrors, hopes, and humanity of the war. Dr. Jeff Gusky has announced his discovery of the art in these underground cities, publishing 2,000 photographs of graffiti: writings in pencil, cartoons, sculptures, and carvings.
National Geographic has published an article on this discovery, with an accompanying photo gallery of the art found in these subterranean hide-a-ways. The following video is a brief interview with Dr. Gusky.